TFT array substrate and the fabrication method thereof

Abstract

A TFT array substrate includes: a gate electrode connected to a gate line; a source electrode connected to a data line crossing the gate line to define a pixel region; a drain electrode which is opposite to the source electrode with a channel in between; a semiconductor layer defining the channel between the source electrode and the drain electrode; a pixel electrode in the pixel region and connected to the drain electrode; a channel passivation layer on the channel of the semiconductor layer; a gate pad extending from the gate line, where a semiconductor pattern and a transparent conductive pattern are formed; a data pad connected to the data line, where the transparent conductive pattern is formed; and a gate insulating layer formed under the semiconductor layer, the gate line and the gate pad, and the data line and the data pad.

Description

[0001]This application claims the benefit of Korean Patent Application No. 117242 / 2004, filed on Dec. 30, 2004, which is incorporated by reference for all purposes as if fully set forth herein.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to a thin film transistor (TFT) array substrate, and more particularly, to a TFT array substrate capable of preventing pad corrosion as well as protecting a TFT without any passivation layer, and the fabrication method thereof.[0004]2. Discussion of the Related Art[0005]A liquid crystal display device (LCD) displays an image by controlling the light transmittance of liquid crystal (LC) using an electric field.[0006]The LCD drives liquid crystal using an electric field formed between a pixel electrode and a common electrode respectively disposed on an upper substrate and a lower substrate facing each other.[0007]The LCD has a TFT array substrate (lower array substrate) and a color filter array substrat...

AI Technical Summary

Benefits of technology

The solution effectively protects TFTs without a passivation layer, reduces mask processes, prevents corrosion, and enhances production yield by using a transparent conductive layer for repair and electrostatic protection, leading to improved image quality and reduced defects.

Problems solved by technology

In the LCD, as the TFT array substrate requires a semiconductor process and a plurality of mask processes, the manufacturing process thereof is complicated and thus the manufacturing cost increases.

Because the PECVD apparatus, the spin coating apparatus, or the spinless coating apparatus are required to form the passivation layer 18 as descried above, the manufacturing cost increases.

Also, image quality degradation (e.g., spots) results due to the relatively low capacitance of the storage capacitor 40.

Also, because the data pad is opened when the passivation layer is formed, a defect (e.g., galvanic corrosion of a data pad) may be generated during a subsequent process.

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